bancroft



Feb. 3, 1931. u J, E, BANCRQFT A 1,790,648

DoR OPERATING MEcHANIsM Filed Mayl 2, 1928 'I Q .1e/

MIL'.

mvENToR vv ITN E55 r/AWES I BANG/wf? Patented Feb. 3, 1931 l Unirse STATES JAMES E. IBAITCROFT, OF DETROIT, MICHIGAN, ASSIGNOR-T'O DOORJMOTIVE CORPORA- TION, 0F WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHTISIilLTSl noon-ornaafrrne ivrncmiirslnk Application med May 2,

This invention relates to door operating mechanism and more particularly to power actuated apparatus arranged to open and closelarge doors.

It has heretofore been proposed toutilize an electric motor for the operation of doors, but these previous constructions have usually employed various complicated and expensive types of reducing gears in order to transform lthe comparatively rapid speed of the motor down to a relatively slow speed suit!v able for the movement of the doors. f

It is accordingly one object of my invention to provide a door operating mechanism actuated by an electric'motor which will operate the doors at a desired speed without the necessity of utilizing complicated speed reduction devices and which will be'inexpensive to manufacture and simple to erect and install.

Various problems arise in designing a door operating mechanism which is adaptable to various forms of existing installation of doors. It frequently happens that the ceilin oV is low and the space between the top of the door and the ceiling is therefore small1 making it difficult to install the mechanism in such a small space. It also "frequently happens that there is a wall perpendicular to the normal closed position of the door which is near the door at one or both sides thereof and therefore limits the space within which the door operating mechanism may be installed.

It is accordingly a further object of my invention to provide door operating mechanism which will require a minimum of space and can be easily installed in connection with existing door vinstallations where the door extends nearly to the ceiling or where there is some other obstruction limiting the available space, and-particularly one which is well adapted forfuse in connection with doors of theswinging or folding type.

With these and other objects in view as will be apparent to thoseA skilled in the art` my invention resides in the combinationof parts set forth in the specification and covered by the claims appended hereto.

In accordance with my invention and to 192e. ssriai No. 274,511.

\ ranged to move in substantially a straight line as the door is opened or closed.V IprefmsY erably' rotate the screw and this may be done by connecting it directly to the motor by means of a suitable flexible coupling so that the screw is rotated at motor speed' and is free to swing slightly and thus avoid the transmission of any bending action tothe motor shaft. When the doors to be'operated Vare of the swinging or foldingtype, the nut is connected tothe door through' a suitable linkageso as to cause it to move in substanits hinges. v

`Referring to the tiallv a straight line as the door swings about f drawings illustrating one embodiment of my invention and in which like reference numerals indicatelilze parts: Fig. 1 is a plan view of my apparatus "appliedito a set of folding doors, the doors being shown in the closed positionand certain parts being removed and others broken away for clearness of illustration; 'Y

Fig. 2 is a plan view of the installation shown in Fig. 1, with the doors shown in the open position;

Fig. 3 is a front elevation of the installation shown inFig. vLvvith the doors shown in the closed position;

Fig. 4 is a sideV elevation of'al portion of the apparatus, showing the method of connecting the varm and link to the doorA and lintel; andy Fig. 5 is a side elevationv showing one method of mounting the motor and limit switch.Y -fv The embodiment of my invention illustrated in the drawings comprises a door operating mechanism installed to operate a set of doors of the folding type. As shown,

a wall may be provided with a rectangular opening therethrough andarranged to form :a casing for the doors. A pair of doors 11 and 12 are hinged to the door casing at 14 and 15 respectively, so that they may swing about vertical axes on opposite sides of the casing. A second pair of doors 17 and 18 are hinged to the first doors at 2O and 21 respectively, so that they may fold against the doors 11 and 12 when they are in the open position, Vas shown in Fig. 2. Various arrangements may be employed to guide the free edges of the doors 17 and 18 as they move from open to closed position and vice versa. @ne simple means well known in the art coniprises a. pair of arms 23 and 24 which are pivoted to the doors 17 and 18 at the points 26 and 27 respectively. rlhese arms are long and their opposite ends not shown) are fulcruined to a suitable stationary support such as the ceiling or a beam'. In this manner the free edges'of the doors 17 and 18 are kguided in an arc of acircle having a comparatively long radius. Y

In order to open and close the doors by power I provide 4a suitable motor, preferably an electric motor 29. This motor may be mounted slightly above the top of the doors, and if the ceiling is low it may be attached directly thereto. In the drawings I have shown the motor attached to a bracket 30 which is mounted on the wall 10 abo-ve the doors. In Fig. 1 this bracket has been removed, in. order to show the construction underneath. y

Since electric motors ordinarily used for door operation rotate at a comparatively high speed, it is necessary to use some form of speed reducing mechanism ytoconnect the motorto the doors-in order that they may open and close at the desired speed. I have found a screw and nut to be particularly desirable for this Vpurpose and accordingly when the doors are of the double type shown in thefdrawings, I provide a pair of screws 32 and 33 which are threaded through nuts 35 and 36. Either of these parts maybe rotated Vand the other parts connected to the doors to move the same.A In the preferred embodiment of the invention illustrated I have shown the screws 32 and 33 as being rotated by themotor 29 and the nuts 35 and 36 are connected tothe doors by a suitable means so that thedoorslopen and close the nuts move back and forth ralong the screws. These screws are of Yopposite hand, as shown, screw 32 having a left hand thread and screw 33aright hand thread.

The nuts'are connected to the doors in suchY For pivotal points 41 and 42 are spaced a considerable distance from the hinges 14 and 15. The arms 38 and 39 are provided on their undersides with braces 44 and 45 respectively in order to strengthen them and permit them to support the weight ofv the parts resting thereon without sagging. Links 47` and 48 are provided, each having one end pivoted to the casing at points 50 and 51 respectively between the arm and the corresponding door hinges. Each link 47 and 48 is pivotally joined at its outer end to the adjacent arm at points 53 and 54 respectively'. The linksare made of such sizes and relative Vproportions that they will fold into a comparatively small space when the doors are vopen as shown in Fig. 2-and thus avoid'any interference with the ad] acent wall 55 shown in the drawings.

The nuts 35 and 36 are mounted upon the' arms-38 and 39 at points which are so-selected that the nuts move in substantiallya straight line parallel to the door casing during the operation of the doors. Each nut is free-to rotate relative to its corresponding arm about a vertical axis, as shown in Fig. 4. For

this purpose the nuts 35 and 36 are mounted in Vyokes57 and 58`which are provided .with

downwardly extending `spindles 60 andy61 respectively. Thesespindles'are free to lrotate in suitable bosses 63 and 64 in the arms and braces. Each nutfis preferably pivotally mounted about a horizontal axis in itscorresponding yoke as illustrated. This construction forms a universal mounting for the nuts so that they are free to align themselves with the screws, thereby preventing any binding between the nuts and screws which might be caused by slight 'errors 'in alignment or -saggingof the doors Since the .construction described does not giveV a perfect straightline motion tothe nut -it is necessary to lpermit the screws to swing slightlyduring operation ofthe doors. I

.therefore provide .universal couplings `66 and torshaft andconn'ect it by means of'achain 71 to a second sprocket 72 which operates an enclosed Vlimit switch 74. This Vlimit switch, which-may be convenientlymounted beneath the' motor supporting bracket-30, may be of any suitable construction wellknown to those skilled inthe art. Since various methods of operating .doory mecha- `msm of this general type are'well-known to those skilled inthe art, suchas push :but-

tons, licor trips, etc., I have not Villustrated any particular arrangement for Vthe electriproach either of their extreme positions the limit switch operates to break the motor circuit and bring thedoors to a stop. Since the motor is the highest part of the Whole mechanism, the apparatus canbe used in connection with existing door installations where the space is very limited. rlhe mec-ha-Y nism is simple and inexpensive to manufacture and all gearing has been eliminated.

In case of ordinary double swinging doors which do not have the folding feature, the operation will be identical. In such a case the parts 17 and 18 will be made integral with the doors 11 and 12 and the members 23 and 24 will not be utilized.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. A device for operating a door hinged to a casing and arranged to swing about a vertical axis, comprising an arm having one end adapted to be pivoted to the door at a point spaced from said axis, a link having one end arranged to be pivoted to the casing at a point between the arm and 1 the axis, said arm and said link being pivotally joined at their outer ends, a nut mounted on said arm and yarranged to revolve relative thereto about a vertical axis, a screw threaded throughL the nut, and a motor connected to the screw to rotate the same, whereby operation of the motor will cause the door to open or close.

2. In combination, a` door casing, a door hinged to the casing and arranged to swing about a vertical axis, an arm having one end pivoted to the door near its top and at a point spaced from said axis, a link having one end pivoted to the casing above the door and at a point between the arm and the axis, said arm and said link being pivotally joined at their outer ends, a nut mounted on said arm intermediate of its length and arranged to revolve relative thereto about a vertical axis, a screw threaded through the nut, a rotatable motor, and a universal coupling connecting the motor directly to the screw, whereby operation of the motor will open or close the door.

3. In combination, a door casing, a pair of doors hinged to the casing and arranged to swing about vertical axes on opposite sides of the casing, a pair of arms each having one end pivoted to one of the doors at a point spaced from the door axis, a pair of links each having one end pivoted to the casing at a point between one of the arms and the door axis, each arm and the adjacent link being pivotally joined at their outer ends,a nut mounted on each arm intermediate of its length and free torevolve relative thereto about a vertical axis, a pair of screws of opposite hand, each being threaded through one of the nuts, a rotatable motor provided with a shaft `extension at each end thereof, and universal couplings connecting each screw with one end of the motor shaft, whereby operation-of the motor will open or close the doors simultaneously.

4. In combination, a door casing, ajpair of doors hinged to the casing and arranged to swing about vertical axes on opposite sides of the casing, a pair of arms each havingone end pivoted to one of the doors near its top and adjacent to the edge opposite its hinge, a pair of links each having one end pivoted to the casingv above the door at a point between'one of the arms and the kdoor axis, each arm and the adjacent link being pivotally joined at their outer ends, a nut mounted on each arm intermediate of its length and free to revolve relative thereto about a vertical axis, a pair of screws of opposite hand, each being threaded through one of the nuts, an electric motor provided with a shaft extension at each end thereof, universal couplings connecting each screw with one end of the motor Shaft, a second pair of doors each of which is hinged to lone of the first mentioned doors, and means to guide the free edges of the second doors as Vthe first doors are opened and closed by the operation of the motor.

Signed at Detroit, Michigan, this 27th day of April, 1928.

JAMES n. BANoRorT. 

